香根草油是從香根草（Vetiveria zizanioides（L.）Nash）的根中提取的一種植物精油,在香料工業(yè)中常被大量用作主要的調(diào)香成分,而且在食品工業(yè)中也可用作調(diào)味劑。由于香根草油用途廣泛,且具有抗氧化、抗菌、消炎等生物活性,近年來有大量有關其提取技術和成分分析的研究報道,研究熱點圍繞如何降低生產(chǎn)成本及環(huán)境污染,以滿足日益增長的市場需求。二氧化碳膨脹乙醇（CO₂ expanded ethanol,CXE）是一種環(huán)境友好的新型綠色溶劑,提取的效率及成本與傳統(tǒng)蒸餾法相當,并高于超臨界二氧化碳萃取。本研究經(jīng)優(yōu)化得到最優(yōu)的工藝操作條件,與水蒸汽蒸餾工藝和超臨界流體萃取工藝進行比較,評估新工藝的特點及可行性。由于香根草的化學成分復雜,香氣及功效成分含量低,傳統(tǒng)方法很難進行分離鑒定。本研究對香根草油進行了二級分子蒸餾,去除了大部分非揮發(fā)成分,顯著增強色譜峰分離度,對有效成分進行了富集,結合GC-MS精油的組成分析,鑒定主要的特征性香氣成分、抗菌成分及抗氧化成分,為制定產(chǎn)品質(zhì)量標準提供理論依據(jù),同時考察分子蒸餾用于精制香根油的可行性。CXE是一種混合流體,由主體的極性... 

【文章來源】：浙江師范大學浙江省

【文章頁數(shù)】：110 頁

【學位級別】：碩士

【文章目錄】：
ABSTRACT
摘要
Chapter Ⅰ.Literature review
    1.Vetiver grass and vetiver essential oil
        1.1 Morphological description of vetiver grass
        1.2 Various uses of vetiver grass
        1.3 Background and properties of vetiver oil
        1.4 Annual market demand of vetiver oil
        1.5 Chemical composition analysis of vetiver root oil
    2.Extraction techniques of vetiver oil
        2.1 Hydrodistillation
        2.2 Supercritical fluid extraction
        2.3 Carbon dioxide expanded ethanol
            2.3.1 Characterization of carbon dioxide expanded ethanol fluid
            2.3.2 Physico-chemical properties of carbon dioxide expanded ethanol fluid
            2.3.3 Applications of CO2 expanded ethanol extraction
    3.Refining process of vetiver oil by molecular distillation
        3.1 Description of the molecular distillation process
        3.2 Basic principles of molecular distillation
        3.3 Applications of molecular distillation technique
    4.Research purpose,significance and main research content
        4.1 Research purpose and significance
        4.2 Main research contents
        4.3 Schematic representation of research
Chapter Ⅱ.Conventional extraction techniques of vetiver root oil
    1.Introduction
    2.Experimental materials and methods
        2.1 Experimental materials,reagents and instruments
            2.1.1 Preparation of vetiver root
            2.1.2 Experimental reagents
            2.1.3 Experimental instruments
        2.2 Experimental methods
            2.2.1 Hydrodistillation
            2.2.2 Indirect vapor distillation(live steam distillation)
            2.2.3 Supercritical fluid extraction
            2.2.4 Estimation of vetiver oil yield
    3.Results and discussions
        3.1 Effect of extraction techniques on the yield of vetiver oil
        3.2 Investigation of isolation conditions for hydrodistillation
            3.2.1 Effect of matrix-to-liquid ratio on the extraction rate of vetiver root oil
            3.2.2 Effect of root particle size on vetiver oil yield
            3.2.3 Effect of distillation time on the yield of root oil
        3.3 Selection of extraction conditions for supercritical fluid extraction
            3.3.1 Effect of extraction time and CO2 flow rate on vetiver oil yield
            3.3.2 Effect of pressure and temperature on the SFE extraction process
    4.Summary
Chapter Ⅲ.Optimization of vetiver oil extraction by Carbon Dioxide Expanded Ethanol..
    1.Introduction
    2.Experimental materials and methods
        2.1 Experimental materials,reagents and instruments
            2.1.1 Pretreatment of vetiver root
            2.1.2 Experimental reagents
            2.1.3 Experimental instruments
        2.2 Experimental methods
            2.2.1 Carbon dioxide expanded ethanol extraction
            2.2.2 Calculation of root oil yield and CO2 mole fractions
            2.2.3 Design of response surface methodology
            2.2.4 Gas chromatographic/Mass Spectrum analysis for the composition of the vetiver oils
            2.2.5 Alternatives for evaporation of solvent from CXE extract
            2.2.6 Detection of heavy metals(Fe,Cu,Cd)in vetiver root material and oils
    3.Results and discussion
        3.1 Optimization of extraction conditions for CO2 expanded ethanol extraction
            3.1.1 Experimental design and result of Response surface methodology
            3.1.2 Fitting model and significance
            3.1.3 Analysis of optimized factors influencing CXE extraction
            3.1.4 Determination of optimum condition of CXE extraction
        3.2 Chemical analysis of vetiver oils obtained by traditional and green extractions
        3.3 Alternatives of solvent evaporation from CXE vetiver extracts
        3.4 Investigation of heavy metals(Fe,Cu,Cd)in root material and vetiver oils
    4.Summary
Chapter Ⅳ.Refinement of root oil from Vetiveria zizanioides(L.)Nash using two-stage molecular distillation process
    1.Introduction
    2.Experimental materials and methods
        2.1 Materials,reagents and instruments
            2.1.1 Experimental materials
            2.1.2 Experimental reagents
            2.1.3 Experimental instruments
        2.2 Experimental methods
            2.2.1 Description of two-stage of molecular distillation process
            2.2.2 Estimation of molecular distillation parameters
            2.2.3 Estimation of the recovery of vetiver fraction
            2.2.4 Chemical analysis for composition of distillate fractions
    3.Results and discussion
        3.1 Investigation of optimum conditions during the first stage of molecular distillation
            3.1.1 Selection of optimum feeding temperature
            3.1.2 Determination of optimal evaporator temperature
            3.1.3 Effects of feed flow rate and rotor speed on evaporation status
        3.2 Determination of optimum conditions for the second stage of molecular distillation
            3.2.1 Selection of optimum first condenser temperature
        3.3 Chemical composition analysis for the first stage of molecular distillation
        3.4 Chemical analysis for second stage of molecular distillation
    4.Summary
Chapter Ⅴ.Antioxidant activity of vetiver oils and distillate fractions
    1.Introduction
    2.Experimental materials and methods
        2.1 Experimental materials,reagents and instruments
            2.1.1 Experimental materials
            2.1.2 Experimental reagents
            2.1.3 Experimental instruments
        2.2 Experimental methods
            2.2.1 Determination of DPPH free radical scavenging capacity
            2.2.2 Determination of ABTS free radical scavenging
    3.Results and discussion
        3.1 Comparison of DPPH·assays for traditional and CXE vetiver oils
        3.2 ABTS free radical scavenging analysis of vetiver oils
        3.3 DPPH free radical scavenging activity of vetiver distillate fractions
    4.Summary
Chapter Ⅵ.Antimicrobial activity of vetiver oils
    1.Introduction
    2.Experimental materials and methods
        2.1 Experimental materials,reagents and instruments
            2.1.1 Experimental materials
            2.1.2 Experimental reagents
            2.1.3 Test bacterial strains
            2.1.4 Experimental instruments
        2.2 Experimental methods
            2.2.1 Bacterial culture medium
            2.2.2 Preparation of bacterial suspension
            2.2.3 Determination of minimum inhibitory concentration(MIC)
    3.Results and discussion
        3.1 Antimicrobial ability of vetiver oils extracted by conventional and green techniques
    4.Summary
Chapter Ⅶ.Conclusion and prospect
    1.Conclusions
    2.Prospect
References
Research achievements during research
Acknowledgement



本文編號：3261654